Known prior art fluid-damped elastomeric mounts generally are of three types. A first type is a basic bushing having opposed fluid reservoirs which communicate through inertial track capillaries, and is normally used in automotive suspension components requiring a single axis damping. A second type of fluid-damped elastomeric mount is a modified bushing incorporating a "dash pot" type viscous damping that forces fluid past a baffle when axial movement occurs, and is typically used in automotive shock/strut components. A third type is a basic fluid-damped mount having dual fluid chambers communicating through an inertial track and decoupler system together with a fluid return mechanism.
However, all of the above-described known prior art fluid-damped elastomeric mounts typically have a number of inherent problems which make them labor and/or equipment and cost intensive to varying degrees. First, the design of the elastomeric mounts is relatively complicated to provide for anticipated forces and displacements, and also must provide for a permanent hydraulic pressure seal to maintain the fluid in place in the part. Second, introduction of the fluid into the fluid cavity and accessory parts such as the inertial track and/or decoupler system is difficult, with two methods generally being currently employed. In one method, the components of the elastomeric mount can be assembled and sealed while submerged in a fluid bath, or in another method, after assembly and sealing of the elastomeric mounting components, the fluid cavity can be evacuated and filled with the selected fluid. After assembly, filling and sealing of the elastomeric mount, the mount must be carefully checked for leaks and dynamic characteristics. As set forth above, such methods of forming the elastomeric mounts can be labor and/or equipment and cost intensive.
Moreover, such methods of fluid filling and pressure sealing the elastomeric mounts can be damaging in applications where electro-rheological fluid damping is called for. Such fluids change density in response to the application of an electrical charge and thereby change the damping characteristics of a mount. Such systems require precise placement of wires, contacts, connectors, sensors, etc., which are sensitive to damage, displacement, or contamination. Therefore, the two, above-described methods heretofore used for assembling, filling and sealing fluid-damped elastomeric mounts can pose problems. Specifically, assembling and sealing elastomeric mounting components while submerged in a fluid bath or alternatively assembling and sealing the elastomeric mount and separately filling the mount, subjects sensitive electrical components to hostile environments and contaminants such as liquid, heat, and heavy presses and further presents difficulties in the context of an assembly line environment.
The closest known prior art to the present invention is set forth immediately below.
U.S. Pat. No. 4,593,891 relates to a vibration-absorbing engine mounting device with fluid damping which comprises an upper mounting member, a lower mounting member, a rubber wall body interposed between both the mounting members with its upper and lower portions being air-tightly sealed to the upper and lower mounting members respectively, a block damper transversely provided in the rubber wall body, and a capsule encased in a space enclosed by the former four members, thus defining a closed chamber enclosed by the former five members. The capsule comprises an exterior rigid case, an interior sealed bag encapsulated in the rigid case, defining a sacciform chamber and an orifice member entering the former two. The closed chamber and the sacciform chamber are filled with fluid, whereby they are put in communication with one another by the passage of fluid via the orifice member.
U.S. Pat. No. 4,613,118 relates to a fluid-sealed engine mounting comprising a connector for being connected to an engine, a base for being mounted on a vehicle frame, and an elastic member joining the connector to the base, the connector, the base, and the elastic member jointly defining a fluid chamber in which a fluid is sealed during assembly of the mount. The fluid-sealed engine mounting has a variable-volume member mounted on one of the connector and the base in the fluid chamber and containing at least a gas capable of negative atmospheric or positive pressure sealed therein, the first variable-volume member being expandable and contractible in a direction in which vibrations are transmitted in the fluid chamber.